I am currently trying to write an Audio Player in C#. I am using BASS library to deal with playing music but now i have small problem with getting length of the song.
You can use the Microsoft.WindowsAPICodePack.Shell:
using Microsoft.WindowsAPICodePack.Shell;
Then code like so:
string file = "myfile.mp3"
ShellFile so = ShellFile.FromFilePath(file);
double 100nanoseconds;
double.TryParse(so.Properties.System.Media.Duration.Value.ToString(), out 100nanoseconds);
There is a code project that could help you as well